In recent years, there has been a demand for devices capable of detecting dangerous chemicals, such as chemical warfare agents, explosives, and toxic industrial chemicals, from a safe distance. Ideally, such devices should be able to collect both solid and liquid aerosols, as well as vapors, from a remote site and analyze the collected materials for the presence of the chemicals of interest. Since the chemicals of interest may be present at a very low concentration (e.g., on the order of parts per billion (ppb) or less), such devices need to be highly sensitive with low false positive and false negative rates.